What is Trigger Finger?
Trigger finger, also known as ‘stenosing tenosynovitis’ is a condition in which a finger becomes locked in an inwardly curved or flexed position, without being able to straighten it. If movement is attempted by force, there may be a snapping sound that resembles a ‘pistol trigger’ being pulled and released. This is why the condition is termed ‘trigger finger’.
Trigger finger usually occurs due to swelling and inflammation of a tendon, which is a fibrous tissue that connects muscles to bones. The condition is generally associated with stiffness, pain, and swelling. This can result in a round, painful lump (nodule) on the palm, at the base of the affected finger. The thumb can also be affected, in which case, the condition is called ‘trigger thumb’.
What are the Causes & Risk Factors of Trigger Finger?
There may be several causes for trigger finger, but these are not always clear. Some of the causes are briefly highlighted below:
- Tendon Inflammation: This is the primary cause of trigger finger. The tendon is covered by a sheath, through which the tendon is able to slide smoothly as the finger bends and straightens. In trigger finger, this smooth gliding movement is lost as the tendon becomes inflamed, resulting in locking of the affected finger.
- Preexisting Health Conditions: Diseases such as type-2 diabetes mellitus, rheumatoid arthritis and
gout are risk factors for trigger finger.
- Repetitive Gripping Motion: Activities that involve repetitive, strong gripping / grasping or forceful use of the fingers and/or thumbs can cause trigger finger. It is common in farmers, industrial workers and musicians, who perform repetitive tasks with their fingers.
- Surgery for Carpal Tunnel Syndrome: Trigger finger can result as a complication of carpal tunnel syndrome surgery.
- Gender and Age: Gender and age are important risk factors for trigger finger, which is more prevalent in women and is more common in the age-group of 40-60 years.
- Trigger Finger - Mayo Clinic - (https://www.mayoclinic.org/diseases-conditions/trigger-finger/symptoms-causes/syc-20365100)
- Trigger Finger - American Society for Surgery of the Hand (ASSH) - (https://www.assh.org/handcare/hand-arm-conditions/trigger-finger)
- Trigger Finger - American Academy of Orthopedic Surgeons - (https://orthoinfo.aaos.org/en/diseases--conditions/trigger-finger)
- About Trigger Finger - Cleveland Clinic - (https://my.clevelandclinic.org/health/diseases/7080-trigger-finger--de-quervains-disease)
- Trigger Finger/Thumb - Medline Plus - (https://medlineplus.gov/ency/patientinstructions/000565.htm)